Presence and Distribution of Leptodactylus Guianensis Heyer and de Sa, 2011 in Colombia: Comparisons with Other Species in the L. Latrans Group.

Leptodactylus guianensis is reported for the first time for Colombia along with a distributional map of the species. The species is the fifth species of the L. latransspecies group documented in the country. Males possess a single, conical and slightly chisel-shaped thumb spine; only three species in the group have a single thumb spine. In collections, specimens of L. guianensis are misidentified as L. macrosternum, L. latrans or L. bolivianus. We provide morphological, colouration and habitat descriptions for where the species occurs in Colombia

YqiC of Salmonella enterica serovar Typhimurium is a membrane fusogenic protein required for mice colonization

<p>Abstract</p> <p>Background</p> <p><it>Salmonella enterica </it>serovar Typhimurium is an intracellular bacterial pathogen which can colonize a variety of hosts, including human, causing syndromes that vary from gastroenteritis and diarrhea to systemic disease.</p> <p>Results</p> <p>In this work we present structural information as well as insights into the <it>in vivo </it>function of YqiC, a 99-residue protein of <it>S</it>. Typhimurium, which belongs to the cluster of the orthologous group 2960 (COG2960). We found that YqiC shares biophysical and biochemical properties with <it>Brucella abortus </it>BMFP, the only previously characterized member of this group, such as a high alpha helix content, a coiled-coil domain involved in trimerization and a membrane fusogenic activity <it>in vitro</it>. In addition, we demonstrated that YqiC localizes at cytoplasmic and membrane subcellular fractions, that a <it>S</it>. Typhimurium <it>yqiC </it>deficient strain had a severe attenuation in virulence in the murine model when inoculated both orally and intraperitoneally, and was impaired to replicate at physiological and high temperatures <it>in vitro</it>, although it was still able to invade and replicate inside epithelial and macrophages cell lines.</p> <p>Conclusion</p> <p>This work firstly demonstrates the importance of a COG2960 member for pathogen-host interaction, and suggests a common function conserved among members of this group.</p

Genetic characterization by amplified fragment length polymorphism (AFLP) markers and morphochemical traits of Carica papaya L. genotypes

Carica papaya L. is a native fruit from Central America and Mexico and it is an economically important fruit. As a pre-breeding genetic study, the variability of both parents (L7 and M22) and the F1 individuals derived from their crosses (L7 × M22), was evaluated in terms of 32 morphochemical traits, and contrasted with their genetic diversity indicated by amplified fragment length polymorphism (AFLP) markers. According to morphochemical traits, L7 and M22 were grouped in two different clades. The first group included L7 and 13 genotypes from the F1, while a second group included the parent M22 and 15 other genotypes from the F1 progeny. The analysis based on morphochemical traits showed an average correlation of 0.652 among genotypes. For AFLP analysis the combination of the primers E-ACA/M-CTA had the best polymorphic index (72.73%). When they were grouped based on AFLPs markers, it was confirmed that both parents are genetically distant, and they were again grouped in two different clades. Five genotypes from the F1 population were grouped in the same clade as L7 and shared 55% similarity. Twenty six genotypes were grouped in the same clade as M22, showing 63.3% similarity. Another 12 genotypes (mainly female genotypes) were grouped in a third independent clade. This relative general agreement between the grouping based on a large number of morphochemical traits (including both plant and fruit traits) and that based on its genetic diversity using AFLPs, suggests that morphochemical characterization, together with genetic analysis by AFLPs, can be complementary and useful techniques for the identification and assessment of genetic diversity within C. papaya L. genotypes, that should be useful for genetic breeding programs of this important species.Key words: Morphological markers, AFLP markers, genetic similarity, Carica papaya L

Constraining the physics of carbon crystallization through pulsations of a massive DAV BPM37093

We are trying to reduce the largest uncertainties in using white dwarf stars as Galactic chronometers by understanding the details of carbon crystalliazation that currently result in a 1–2 Gyr uncertainty in the ages of the oldest white dwarf stars. We expect the coolest white dwarf stars to have crystallized interiors, but theory also predicts hotter white dwarf stars, if they are massive enough, will also have some core crystallization. BPM 37093 is the first discovered of only a handful of known massive white dwarf stars that are also pulsating DAV, or ZZ Ceti, variables. Our approach is to use the pulsations to constrain the core composition and amount of crystallization. Here we report our analysis of 4 hours of continuous time series spectroscopy of BPM 37093 with Gemini South combined with simultaneous time-series photometry from Mt. John (New Zealand), SAAO, PROMPT, and Complejo Astronomico El Leoncito (CASLEO, Argentina).Fil: Nitta, Atsuko. Gemini Observatory; Estados UnidosFil: Kepler, S. O.. Universidade Federal do Rio Grande do Sul; BrasilFil: Chené, André Nicolás. Gemini Observatory; Estados UnidosFil: Koester, D.. Universitat Kiel; AlemaniaFil: Provencal, J. L.. University of Delaware; Estados UnidosFil: Kleinmani, S. J.. Gemini Observatory; Estados UnidosFil: Sullivan, D. J.. Victoria University of Wellington; Nueva ZelandaFil: Chote, Paul. University of Warwick; Reino UnidoFil: Sefako, Ramotholo. South African Astronomical Observatory; SudáfricaFil: Kanann, Antonio. Universidade Federal de Santa Catarina; BrasilFil: Romero, Alejandra D.. Universidade Federal do Rio Grande do Sul; BrasilFil: Corti, Mariela Alejandra. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Kilic, Mukremin. University of Oklahoma; Estados UnidosFil: Montgomery, M. H.. University of Texas at Austin; Estados UnidosFil: Winget, D.. University of Texas at Austin; Estados UnidosXXIX IAU General AssemblyHonoluluEstados UnidosInternational Astronomical Unio

Time series spectroscopic and photometric observations of Massive DAV BPM37093

BPM 37093 was the first of only a handful of massive (1.05+/-0.05 Msun; Bergeron et al. 2004; sitta 2000) WD pulsators discovered (Kanaan et al. 1992). These stars are particularly interesting because the exact process of core crystallization (Abrikosov 1960; Kirzhnitz 1960; Salpeter 1961). is poorly constrained by observation, yet adds a 1?2 Gyr uncertainty in the ages of the oldest white dwarf stars observed and hence, in the ages of associations that contain them. Last year, we discovered that ESO uses BPM 37093 as standard star and extracted corresponding spectra from the public archive. The data suggested a variation in the observed hydrogen line profiles that could potentially be due to pulsations, but the measurement did not reach a detection-quality threshold. To further explore this possibility, though, we obtained 4hrs of continuous time series spectroscopy of BPM37093 with Gemini in the Northern Spring of 2014. We present our preliminary results from these data along with those from the accompanying time series photometric observations we gathered from Mt. John (New Zealand), SAAO and PROMPT　to support the Gemini observations.Fil: Atsuko, Nitta. Gemini Observatory; Estados UnidosFil: Kepler, S. O.. Universidade Federal do Rio Grande do Sul; BrasilFil: Chené, André Nicholas. Gemini Observatory; Estados UnidosFil: Koester, D.. Universitat Kiel; AlemaniaFil: Provencal, J. L.. University of Delaware; DinamarcaFil: Kleinmani, S. J.. Gemini Observatory; Estados UnidosFil: Sullivan, D. J.. Victoria University of Wellington; Nueva ZelandaFil: Chote, Paul. Victoria University of Wellington; Nueva ZelandaFil: Safeco, Ramotholo. South African Astronomical Observatory; SudáfricaFil: Kanaan, A.. Universidade Federal de Santa Catarina; BrasilFil: Romero, Alejandra Daniela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; Argentina. Universidade Federal do Rio Grande do Sul; BrasilFil: Corti, Mariela Alejandra. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: Kilic, Mukremin. University of Oklahoma; Estados UnidosFil: Montgomery, M. H.. University of Texas at Austin; Estados UnidosFil: Widget, D. E.. University of Texas at Austin; Estados UnidosEUROWD 14: 19th European White Dwarf WorkshopMontrealCanadáUniversidad de Montrea

The MUSCLES Treasury Survey. I. Motivation and overview

Ground- and space-based planet searches employing radial velocity techniques and transit photometry have detected thousands of planet-hosting stars in the Milky Way. With so many planets discovered, the next step toward identifying potentially habitable planets is atmospheric characterization. While the Sun–Earth system provides a good framework for understanding the atmospheric chemistry of Earth-like planets around solar-type stars, the observational and theoretical constraints on the atmospheres of rocky planets in the habitable zones (HZs) around low-mass stars (K and M dwarfs) are relatively few. The chemistry of these atmospheres is controlled by the shape and absolute flux of the stellar spectral energy distribution (SED), however, flux distributions of relatively inactive low-mass stars are poorly understood at present. To address this issue, we have executed a panchromatic (X-ray to mid-IR) study of the SEDs of 11 nearby planet-hosting stars, the Measurements of the Ultraviolet Spectral Characteristics of Low-mass Exoplanetary Systems (MUSCLES) Treasury Survey. The MUSCLES program consists visible observations from Hubble and ground-based observatories. Infrared and astrophysically inaccessible wavelengths (EUV and Lyα ) are reconstructed using stellar model spectra to fill in gaps in the observational data. In this overview and the companion papers describing the MUSCLES survey, we show that energetic radiation (X-ray and ultraviolet) is present from magnetically active stellar atmospheres at all times for stars as late as M6. The emission line luminosities of C iv and Mg ii are strongly correlated with band-integrated luminosities and we present empirical relations that can be used to estimate broadband FUV and XUV (≡X-ray + EUV) fluxes from individual stellar emission line measurements. We find that while the slope of the SED, FUV/NUV, increases by approximately two orders of magnitude form early K to late M dwarfs (≈0.01–1), the absolute FUV and XUV flux levels at their corresponding HZ distances are constant to within factors of a few, spanning the range 10–70 erg cm−2 s−1 in the HZ. Despite the lack of strong stellar activity indicators in their optical spectra, several of the M dwarfs in our sample show spectacular UV flare emission in their light curves. We present an example with flare/quiescent ultraviolet flux ratios of the order of 100:1 where the transition region energy output during the flare is comparable to the total quiescent luminosity of the star Eflare(UV) ∼ 0.3 L*Δt (Δt = 1 s). Finally, we interpret enhanced L(line)/LBol ratios for C iv and N v as tentative observational evidence for the interaction of planets with large planetary mass-to-orbital distance ratios (Mplan/aplan) with the transition regions of their host stars.Publisher PDFPeer reviewe

The MUSCLES Treasury Survey. IV. : Scaling relations for ultraviolet, Ca II K, and energetic particle fluxes from M dwarfs

Characterizing the UV spectral energy distribution (SED) of an exoplanet host star is critically important for assessing its planet's potential habitability, particularly for M dwarfs, as they are prime targets for current and near-term exoplanet characterization efforts and atmospheric models predict that their UV radiation can produce photochemistry on habitable zone planets different from that on Earth. To derive ground-based proxies for UV emission for use when Hubble Space Telescope (HST) observations are unavailable, we have assembled a sample of 15 early to mid-M dwarfs observed by HST and compared their nonsimultaneous UV and optical spectra. We find that the equivalent width of the chromospheric Ca ii K line at 3933 Å, when corrected for spectral type, can be used to estimate the stellar surface flux in ultraviolet emission lines, including H i Lyα. In addition, we address another potential driver of habitability: energetic particle fluxes associated with flares. We present a new technique for estimating soft X-ray and >10 MeV proton flux during far-UV emission line flares (Si iv and He ii) by assuming solar-like energy partitions. We analyze several flares from the M4 dwarf GJ 876 observed with HST and Chandra as part of the MUSCLES Treasury Survey and find that habitable zone planets orbiting GJ 876 are impacted by large Carrington-like flares with peak soft X-ray fluxes ≥10−3 W m−2 and possible proton fluxes ~102–103 pfu, approximately four orders of magnitude more frequently than modern-day Earth.Publisher PDFPeer reviewe

The High-Energy Radiation Environment Around a 10 Gyr M Dwarf: Habitable at Last?

High levels of X-ray and UV activity on young M dwarfs may drive rapid atmospheric escape on temperate, terrestrial planets orbiting within the liquid water habitable zone. However, secondary atmospheres on planets orbiting older, less active M dwarfs may be stable and present more promising candidates for biomarker searches. We present new HST and Chandra observations of Barnard's Star (GJ 699), a 10 Gyr old M3.5 dwarf, acquired as part of the Mega-MUSCLES program. Despite the old age and long rotation period of Barnard's star, we observe two FUV ($\delta_{130}$ $\approx$ 5000s; $E_{130}$ $\approx$ 10$^{29.5}$ erg each) and one X-ray ($E_{X}$ $\approx$ 10$^{29.2}$ erg) flares, and estimate a high-energy flare duty cycle (defined here as the fraction of the time the star is in a flare state) of $\sim$ 25\%. A 5 A - 10 $\mu$m SED of GJ 699 is created and used to evaluate the atmospheric stability of a hypothetical, unmagnetized terrestrial planet in the habitable zone ($r_{HZ}$ $\sim$ 0.1 AU). Both thermal and non-thermal escape modeling indicate (1) the $quiescent$ stellar XUV flux does not lead to strong atmospheric escape: atmospheric heating rates are comparable to periods of high solar activity on modern Earth, and (2) the $flare$ environment could drive the atmosphere into a hydrodynamic loss regime at the observed flare duty cycle: sustained exposure to the flare environment of GJ 699 results in the loss of $\approx$ 87 Earth atmospheres Gyr$^{-1}$ through thermal processes and $\approx$ 3 Earth atmospheres Gyr$^{-1}$ through ion loss processes, respectively. These results suggest that if rocky planet atmospheres can survive the initial $\sim$ 5 Gyr of high stellar activity, or if a second generation atmosphere can be formed or acquired, the flare duty cycle may be the controlling stellar parameter for the stability of Earth-like atmospheres around old M stars.Comment: Accepted to A

Trabajo, empleo, calificaciones profesionales, relaciones de trabajo e identidades laborales. Vol. I

CLACSO ha apoyado desde sus inicios la constitución y desarrollo de grupos de reflexión centrados en la problemática del mundo del trabajo. Los temas abordados sucesivamente han sido el empleo y el desempleo, los movimientos laborales, las relaciones de trabajo, las condiciones y medio ambiente de trabajo. Las reuniones y seminarios se han desarrollado en las principales ciudades del continente: México DF, La Habana, Medellín, Santiago de Chile, Río de Janeiro, San Pablo, Buenos Aires y Montevideo. Los objetivos son facilitar los encuentros, el debate y las acciones de cooperación entre los especialistas mas reconocidos y con los jóvenes investigadores, becarios, maestrandos y doctorandos y nutrir una comunidad muy diversa, y pluralista de científicos sociales que no han cesado de crecer. Los grupos han reunido a destacados especialistas de la casi totalidad de países de la región, con una composición multidisciplinaria y pluralista que abarca a sociólogos del trabajo y de la educación, cientistas políticos, economístas del trabajo y del desarrollo, abogados laboralistas y psicólogos del trabajo, entre otras. Sus estudios han dado lugar a numerosas publicaciones editadas por CLACSO, la UAM, el PREALC de la OIT, el CEIL PIETTE del CONICET y Trabajo y Sociedad de Argentina, y forman parte de las bibliografías de aquellas disciplinas. Desde 2007 se constituyó el actual grupo "Trabajo, empleo, calificaciones profesionales, relaciones de trabajo e identidades laborales" con sede en la UNAM, sede Iztapalapa y en el CEIL-PIETTE del CONICET. Los dos volúmenes que ofrecemos a la comunidad académica y a los actores sociales contienen la mayoría de las ponencias presentadas en el Seminario de Buenos Aires, realizado en noviembre de 2007.INDICE Presentación del Grupo de Trabajo: Trabajo, empleo, calificaciones profesionales, relaciones de trabajo e identidades laborales Julio César Neffa y Enrique de la Garza Toledo 11 Presentación de la obra: Nuevos y viejos escenarios en el mundo laboral latinoamericano: distintas miradas para su estudio Leticia Muñiz Terra 15 Primera parte Dimensiones teóricas y metodológicas Diez tesis sobre el trabajo del presente (y el futuro del trabajo) Ricardo Antunes 29 Aportes a una teoría del cambio: gubernamentalidad, fuerzas productivas y praxis de sujetos colectivos en nueva época Alberto L. Bialakowsky, María Ignacia Costa y M. Mercedes Patrouilleau 45 um ensaio sobre inércia social Adalberto Cardoso 83 Hacia un concepto ampliado de trabajo Enrique de la Garza Toledo 111 Comentarios: Del trabajo esclavo a las nuevas formas de esclavitud en el trabajo Irene Vasilachis de Gialdino 141 Segunda parte Trabajo, identidad y subjetividad Cuando el trabajo informal es espacio para la construcción de identificaciones colectivas. Un estudio sobre ferias comerciales urbanas Mariana Busso 159 Construcción del sujeto de trabajo en la condición de precariedad Karina Arellano, Diego Baccarelli, Cecilia Dallacia, Lucía De Gennaro, Soraya Giradles y Emilio Sadier 193 Comentarios: Comentarios críticos de las ponencias presentadas en la Mesa Trabajo, identidad y subjetividad Juan Montes Cató 203 Tercera parte Educación, calificación profesional, productividad y salarios Fuentes de la valorización del capital: la relación entre productividad y salarios. Argentina 1993-2006 Javier Lindenboim, Juan M. Graña y Damián Kennedy 215 Demandas empresariales en las estrategias de formación de los ingenieros en dos zonas argentinas Marta Panaia 243 Saberes, intervenciones profesionales y clasificaciones profesionales: nuevos requerimientos a idóneos, técnicos e ingenieros Julio Testa; Claudia Figari y Martín Spinosa 275 Pautas de desigualdad en el mundo social productivo uruguayo. Aportes para el debate en torno a la gestión por competencias Mariela Quiñones Montoro 309 Cuarta parte La nueva dinámica empresarial. Innovación y flexibilización en la industria Trabajo de organización y cadenas de valor. El caso de la vestimenta uruguaya Marcos Supervielle y Emiliano Rojido 337 Potencialidades y limitaciones de sectores dinámicos de alto valor agregado: la industria aeroespacial en México, Jorge Carrillo y Alfredo Hualde 373 La industria del salmón en Chile: ¿crecimiento social o explotación laboral?, Antonio Aravena 397 Rasgos posfordistas en el paisaje laboral de la gran industria del Valle del Cauca colombiano Carlos Mejía Sanabria 42

E2F1-Mediated Upregulation of p19INK4d Determines Its Periodic Expression during Cell Cycle and Regulates Cellular Proliferation

BACKGROUND: A central aspect of development and disease is the control of cell proliferation through regulation of the mitotic cycle. Cell cycle progression and directionality requires an appropriate balance of positive and negative regulators whose expression must fluctuate in a coordinated manner. p19INK4d, a member of the INK4 family of CDK inhibitors, has a unique feature that distinguishes it from the remaining INK4 and makes it a likely candidate for contributing to the directionality of the cell cycle. p19INK4d mRNA and protein levels accumulate periodically during the cell cycle under normal conditions, a feature reminiscent of cyclins. METHODOLOGY/PRINCIPAL FINDINGS: In this paper, we demonstrate that p19INK4d is transcriptionally regulated by E2F1 through two response elements present in the p19INK4d promoter. Ablation of this regulation reduced p19 levels and restricted its expression during the cell cycle, reflecting the contribution of a transcriptional effect of E2F1 on p19 periodicity. The induction of p19INK4d is delayed during the cell cycle compared to that of cyclin E, temporally separating the induction of these proliferative and antiproliferative target genes. Specific inhibition of the E2F1-p19INK4d pathway using triplex-forming oligonucleotides that block E2F1 binding on p19 promoter, stimulated cell proliferation and increased the fraction of cells in S phase. CONCLUSIONS/SIGNIFICANCE: The results described here support a model of normal cell cycle progression in which, following phosphorylation of pRb, free E2F induces cyclin E, among other target genes. Once cyclinE/CDK2 takes over as the cell cycle driving kinase activity, the induction of p19 mediated by E2F1 leads to inhibition of the CDK4,6-containing complexes, bringing the G1 phase to an end. This regulatory mechanism constitutes a new negative feedback loop that terminates the G1 phase proliferative signal, contributing to the proper coordination of the cell cycle and provides an additional mechanism to limit E2F activity